building insight

01/14/2016

A few years ago I was walking through the parking lot of JPL in Pasadena when a license plate caught my eye. It took me a few seconds to figure it out, but it had to be a vanity plate and one I wouldn't mind having. I pointed and exclaimed something like 'how brilliant' to a rather perplexed friend. Just a few days ago someone set a rather amazing Internet ad. It had an easter egg that grabbed my eye for the same reason, although this was much more explicit. There is a connection between the license plate and the ad. I'll get to that, but first I need to talk about some playful tools that physics and astrophysics types use.

Any sort of creative work needs a playful component. Its how you develop your intuition. I'm sure many fields have their own power tools for play and you may want to think about yours as mostly they are so natural that they become part of how we think. You need to try and discard a large number of ideas without fear of failure. Some of these can be rather silly. Often you build toy models in your head or at the blackboard. Typically they aren't practical .. if someone were to ask how many cattle are required to provide shoes for New York City you might say to yourself 'consider a spherical cow'.. Physics problems tend to exclude much of the real world so you can focus on just the bit of interest. Mental or blackboard math rules. You aren't worried about exact answer. I love the power of computer simulations but anything you have to type into would just slow you down and break the flow during the play stage. You want to create little visual models that seem like an extension of your mind so you can dance with them. People develop a certain affinity for numbers and you carry around a few rough rules of thumb. Things like π2 ≈ 10 to about 1.3% .. when you're only worried about 10% errors the arithmetic is easy. Some bits of Nature are stored in this fashion:

° there are π × 107 seconds in a year to better than a half percent

° the speed of light in a vacuum is close to 3 × 108 meters/second. An interesting coincidence is the original definition of a meter was 1/10,000,000 of the distance from the pole to a point on the equator. Distances can be measured in the time light takes to travel the distance. We're used to light days and light years, but light goes about a foot in a billionth of a second or a nanosecond. A very tall friend sometimes gives her height as six and two thirds nanoseconds .. about the time light takes to traverse her length.1

° a light foot is sort of practical when thinking about connecting parts of a computer. If modules are separated by 10 feet, a delay of at least 10 nanoseconds is introduced. This gets interesting when you're using a lot of fiber optics or physical wire as the speed of light is slower.2 The speed of light in the fiber is about 2/3s that of in a vacuum or air. A signal will traverse 1000 km in about 5 thousandths of a second, while a radio wave going through the air only requires 3.3 thousandths of a second. A very long time for a computer. The difference was large enough to justify the construction of a specialized microwave network between Chicago and New York City to give some traders an advantage based on the difference between the index of refraction of air and optical fiber.

° the acceleration caused by Earth's gravity is denoted by g and is roughly 10 meters per second2. It varies depending where you are on the surface, but unless you want to weigh a pound less or more, the rough figure works for quick calculations.

° the diameter of the Sun divided by the height of a person is roughly the same as the height of a person divided by the diameter of a hydrogen atom.

° it takes about 500 seconds for light to travel from the surface of the Sun to the Earth

° photosynthesis in crops and trees is usually under 0.5% efficient

° a cow requires about 10 times as much energy as the plants it eats to produce the same amount of energy

° ...

There are hundreds of little relations like this and a few curious numbers too. One of the most famous is the fine structure constant which describes the strength of electromagnetic interactions between charged particles. It is close to 1/137 and appears in enough calculations that every physicist knows it. If you want to flag one down in a stream of people (airports for example), just write 137 or 1/137 on a piece of paper and hold it in view. I've experimentally found this to be remarkably effective.

Some of the relationships aren't directly connected with Nature, but are just fun and sometimes are even useful. There are too many to list, but here are two..

° e is the base of the natural logarithms and is of fundamental importance to economics and science. It happens to be irrational and transcendental, but the first few digits are easy to remember: 2.7 1828 1828 45 90 45 (1828 repeats twice, and the angles in a right angled isosceles triangle)

° of course there is Hardy–Ramanujan number. The story goes that G. H. Hardy was visiting his friend and colleague Srinivasa Ramanujan in the hospital. He had ridden in cab number 1729 and remarked that it was such a boring number. Ramanujan counted, pointing out that it was the smallest number you can express by cubes in two ways: 13 + 123 and 93 + 103. This has slipped into popular culture and has appeared in both the Simpsons and Futurama in the form of easter eggs. But then again some of the principals of those shows are mathematicians.

And number on a taxi brings us back to the number on a vanity plate. My eye was probably caught by the initial 23, which happens to be my favorite prime, but it looked suspicious - something close to 20 plus π ... I remembered eπ - π is just a bit less than 20. The number on the plate had to be an approximation of eπ. The connection with the ad is perhaps the most beautiful relation in mathematics : 3

eiπ + 1 = 0

While eπ isn't the real thing, it is suggestive enough to bring a smile. Of course there is the possibility the owner just considered eπ cool without thinking of eiπ, but this was the JPL parking lot.

If only vanity plates allowed superscripts...

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1 again an approximation. If you want to do this more exactly the speed is about 0.984 ft/ns ..

2 the speed of light in a material is c/n, where n is the index of refraction. n is close to 1.0 for air, but about 1.5 for optical fiber

In physics experiments signals are delayed with respect others to make logic gates work properly. You develop a sense that 8 inches or 20 centimeters is about a nanosecond in coax.

3 It links the two most important irrational numerical constants e and π, number i which is the base of the imaginary numbers which gives us complex numbers, the additive identity 0 and the multiplicative identity 1. It also answers the question "how many mathematicians does it take to change a light bulb?" Then answer, of course, is -eiπ...

If it seems strange that the exponential of a complex number could be equal to 1, consider what the number e is. It is closely related to compound interest ... ez is the limit of (1 + z/N)N as N goes to ∞. If you set z = iπ and do the math you get -1 + 0i or just -1. Here's an animated gif:

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Recipe Corner

Caramelized Carrots

Ingredients

° 3 pounds of carrots - go for the fancy colored ones if you want it to look good

° salt and freshly ground pepper

° 2 clementines or one large orange

° 1 tbl red wine vinegar

° 3 tbl butter or vegan margarine

° half a bunch of fresh thyme

Technique

° peel the carrots. you can quarter of halve them, but if they're pretty whole carrots with a bit of the tops on are beautiful

° put carrots in a large pan and just cover with water. Add a bit of salt and ground pepper and the clementine juice, the vinegar and butter

° bring to a boil and cook until nearly all the liquid has evaporated

° add the thyme sprigs, reduce heat to low and cook for about 5 minutes to caramelize

12/28/2015

With that he reached into his coat pocket and handed me a screwdriver. I had only met my director once before during the job interview, but here we were in one of the elevators at Bell Labs in Murray Hill about to hack said elevator. A bit of fiddling and the panel was off. He had closed the door and was lighting a small butane powered soldering iron. Friedolf was a known instrumentation expert - a breed as interested in how something is measured as the physics it is after. He made his reputation measuring hydrogen bomb blasts. How much can you accurately measure before your instruments are destroyed. These guys are astonishingly good with physical signals. In under three minutes the panel had been replaced. Spliced into the wiring was an empty connector. We stopped off at the stock room for a few 7400 series ICs and other bits and pieces.

He had worked out the simple logic of the elevator control during an hour of play the day before. The idea was to install a simple state machine - a primitive computer of sorts - that would change the requested floor every once and awhile. Every ten or so trips the elevator indicator would show where the rider intended to go, but bit of kit we installed early the next morning would redirect it to a different floor. We could adjust the period between redirects. It was an excellent introduction to the culture of the place.

A few months in and he called me into his office.

You're working too hard. Why don't you take a week or two off from what you've been doing. Find something interesting to work on. Something different from anything you've worked on or thought of working on. You're not going to learn much in a week, but if you're lucky maybe something will connect in your head. All I ask is you throw yourself into it and tell me about it in a month or two.1

These mini-Sabbaticals generally took place early in January. They continued for a decade until I moved to a different lab and assumed most people were doing something like this. In fact more than a few people created their own paths as part of their research direction - I certainly did - but the instruction to do something very different wasn't as common. My new director called me in and told me about a note describing the week long explorations suggesting it would be important that I stay with it as it had paid off.2 The same note made its way to the third director with the recommendation of the second. After leaving AT&T Research I maintained the tradition. I had made too many connections to different people and fields to give up. While my formal education and much of my work was extremely focused, I had found a mechanism for spreading out and finding a few new dots to connect. It had become something of a serendipity generator. All I have to do is be smart enough to wire in a bit of the new for a new perspective and vision. I'm pretty sure it has made me better at what I do and even how I think.

The 30th of December approaches. That's the day I choose the subject.

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1 This is a rough quote

2 This was remarkable as the divestiture was taking its toll on pure research and the Labs was now business focused. Much has been written on the subject, but the organization and company were poorly suited a competitive world outside the protection of regulated monopoly. The end of an era - that kind of research is very rare these days. But good work is being done in some of government and university labs.

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Recipe Corner

Most of the Christmas cooking consisted of old favorites. I did try a few recipes others suggested. This one is excellent - I used dried cranberries rather than raisins and very good heritage carrots. I'm back to playing with the food and the next post should see something different.

11/10/2015

Around the time cellphones began to become available a story began to circulate.

Early on a Saturday morning in Lancaster County, Pennsylvania an Amish horse-drawn buggy and a Mercedes were in an accident. Both vehicles were too damaged to move and a passenger was injured. Waiting for help to drive by in this rural area might take too long. but fortunately one of the Amish had a cellphone.

The story is apocryphal, but the Amish are often called techno-selectives. The Amish and a few other groups like the Hutterites are conservative Christians known for their resistance to much of modern culture. Old Order Amish reject reject electricity from a public power grid, radio, tv, cars, and contemporary fashion. They operate as collectives and, given the realities of land and supply prices, have become good at business as a survival skill. Some collectives are more progressive than others and have moved into businesses not focused on community support and agriculture adapting modern tools along the way.

Generally the view is technology is usually neutral, but you shouldn't have it if it doesn't promote fellowship. Harold Rheingold noted: For them, it is not just how you use the technology, it is what kind of person you become when you use it.1 Church leaders evaluate technologies rejecting them outright, allowing them with specific restrictions or allow them unconditionally. Rollerblades, boats and barbecues are fine as they bring families and community together while cars, radios and tvs are seen as keeping people apart or as counterproductive distractions. Cellphones may be used in a business, but not within a home. A computer might be part of a dairy business, but it might be in a barn and run by batteries that are recharged with portable generators. The rule making is fascinating as the concept of contemplating how a technology will impact your life is foreign to most of us.

Cellphones not withstanding, the decision to adopt a technology conditionally or unconditionally usually comes when it very mature and most of its new users are technology laggards - the late adopters. A technologies market share over time often has a characteristic S shape.2 The point a technology begins to take off, where it reaches something like a halfway point or a bit beyond, how quickly it grows and its saturation point are fascinating questions for business. Horace Dediu actively asks these questions on his excellent Asymco blog.

Technologies tend to saturate well below the 100% adoption level and although it is a very useful model, the curve isn't quantitatively predictive. I find it very useful to look at the outliers. Why do a very few technologies to very well as well and why many never seem to live up to original expectations" The questions the Amish elders ask form a useful framework. As I get older I'm asking these questions of the things I buy and getting rid of items that fail to serve me well, but this questioning is only in the last decade and is specific to my tastes. To understand it more generally a variety of models can be useful.

Moving away from thinking about people as simple consumers and users (or non consumers or users) of services and devices, you can think of them as networks that are embedded in larger networks. Relationships between people, services, institutions, culture, the law, etc. that are mediated by technologies and how these relate to non-technical relationships. The approach is too broad to consider every possible connectino. Rather the trick is to work out the dominate factors for the problem you're studying.3 It is usually qualitative framework, but you can use the results build semi-quantitative models.

Apple is an interesting example for consideration. Getting deep into detail is beyond the scope of the blog, but this framework shifts it from being a maker of products that may be vulnerable to commodification to a complex web that involved personal style, how others in the social and institutional groups you interact view you, ecosystems of services involving Apple and others, and so on. The iPhone has become central to many users and is a useful lens to flesh out connections. By weighting the network connections you simply the web and begin to look for connected relationships. Links between the nodes can be examined for stickiness and you can imagine how they may evolve over time. Some actions of the company, like focusing on personal privacy, are of particular interest and may give insight into future direction.

Failure can be equally interesting. An example I leave to you is to think about VW and the human centered networks of American vs European diesel buyers...

2 The curve is a sigmoid function of the form f(x) = 1/(1 + e-x). . Note the denominator is huge for large -x and approaches 1 for large x. A more general form is f(x) = C/(1 + e-k(x -x0)), where C is the maximum value of the curve at saturation - eg the total population, k is related to how steep the curve is, and x0 is the 50% point of the curve.

This general form is very common in many disciplines - if you've taken a course in differential equations it is just the solution for f' = f(1-f).

3 This is the fun of the framework. It is very similar to the approach used in physics.

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Recipe Corner

I'm a huge sweet potato fan and love to roast them. It is great for warming the house as the weather chills. The measurements are best guesses here. I started out with equally sized seasonings and adjusted later.

Baked Sweet Potatoes

Ingredients

° 4 medium sweet potatoes

° 1 standard can (15oz) chickpeas drained

° 1/2 tbl olive oil

° 1/2 tsp cinnamon, coriander, cumin and paprika

° 1/2 tsp coriander

° 1/2 tsp cumin

° 1/2 tsp paprika (smoked would be good!)

° sea salt

(sauce)

° 1/4 cup hummus (tahini would also be good)

° juice of 1/2 lemon

° 1 tsp dried dill

° 3 garlic cloves minced

° water to thin

(toppings)

° diced cherry tomatoes

° chopped parsley

° whatever seems interesting... lemon juice, chili sauce...

Technique

° preheat oven to 400°F

° cut sweet potatoes in half lengthwise

° toss the chickpeas with olive oil and place on a baking sheet (I line the sheet with aluminum foil)

° rub the sweet potatoes with olive oil and place face down the the baking sheet

° roast for about 25 to 30 minutes until the chickpeas are golden brown

° while roasting is going on make the sauce by whisking all of the ingredients in a bowl with a bit of water to make it thin enough to pour. Adjust the seasonings.

° toss the toppings if you're using them

° when ready serve the sweet potatoes flat side up, smoosh down the insides a big and top with chickpeas, sauce and add the garish.

10/13/2015

In the early 70s two researchers began to sift through long term weather data-sets hunting for patterns other than seasonal variation. They had access to a late 60s super computer and a powerful processing technique called the Fast Fourier Transform.1

The data set was from an isolated weather station near the equator and international date line. Every day a weather balloon would be tracked created a time series. An interesting pattern emerged - about every month and a half barometric pressure dropped and wind speeds picked up. It looked like the signature of a storm and was interesting enough that they analyzed data from weather stations throughout the region. A weather oscillation in the tropics of the Indian Ocean emerged and was named for them. Now it appears the Madden-Julian oscillation (MJO) is one of the most important weather patterns on the planet.

(click for animation)

Computers and computation have improved enormously in the forty years since the MJO's discovery, but only recently have they been powerful enough to enable researchers to ask questions deep enough to build predictive models. The mechanism is far from well understood, but it appears it impacts other systems. It is connected to Indian and Australian monsoons, the Pineapple Express and perhaps most dramatically for Californians the El Niño.

This year several huge warm wet disturbances have amplified the developing El Niño to produce some intense hurricanes in the Pacific as well as possibly suppressing activity in the Atlantic. California may well be in the crosshairs of an exceptionally strong El Niño event. It is unlikely to bring much drought relief as the snow pack is unlikely to increase much, but it could bring floods and mudslides. Ah the seasons.

Outside of the research community the MJO is not well-known, but understanding it may well be central to understanding weather on the planet and its behavior in a warming world could have dramatic impacts. But if it is only beginning to be understood now why mention it? It turns out enough is known that the uncertainty for certain classes of events has been reduced to the point where predictions can be made. One organization has managed to model it well enough to be able to make accurate enough cold snap predictions over a month out - far enough that traders are using it to make bets on heating fuels.

Science is sedimentary. By the beginning of the 20th century pencil and paper calculations and a few simple measurements were enough to suggest that human caused release of carbon dioxide into the atmosphere could raise the average temperature of the Earth. By the 1960s a clear signal was emerging and a few people began to make predications. By 1980 alarm bells had gone off in the research division of Exxon and at a few University and government labs. The simple models had small enough error bars that it appeared we might be heading for some rather bad sailing. The 90s saw a shrinkage of the error bars along with enough insight that deeper questions arose about mechanisms. Error bars shrunk and new insight and questions came. By around 2000 climate scientists had a sound enough case that most scientists in similar fields were agreeing with them. The signs were strong enough that it was clear action was necessary, but money and politics got in the way.

We won't understand nature perfectly - but there are points along the way where our understanding is sufficient to bring invention and change. There is an art and a science in knowing how to determine when the error bars are small enough to be useful. But progress will continue and maybe we'll get a handle on each of California's seasons.

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1 The CDC 6600 had a 10 MHz clock and 128 K of memory in the $10 million maxed out configuration. Comparisons with current technology are difficult, but the S1 module in the Apple Watch has a clock, slowed for battery life, that is 52 times as fast and 256 K of on-chip memory cache as well as 8 GB of flash that it can access faster than the CDC.

The Fast Fourier Transform reduces the computation required for a Fourier transform from O(n2) to O(n log n) where n is the data size. For realistic data sets this was worth decades of Moore's Law. All of us are aware of the fantastic progress that has been made in silicon over the past six decades, but improvements in algorithms have also made an enormous contribution.

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Recipe corner

No recipe this time other than noting beans are a favorite. I like some of the dried varieties from Rancho Gordo and use their basic bean cooking technique. It will work for any mostly fresh dried beans.

09/25/2015

The structure was small but, despite the amazing view, there was only one small window. A curtain was kept out sunlight. A cluster of electric cables connected the building to the cable car building a thousand feet distant. Twelve is an age when most of us are still at curiosity and society lets us get away with it. I knocked on the door.

My family spent a few weeks each Summer anywhere from the Bob Marshall Wilderness Area in Montana up to Jasper in Alberta. That year it was Banff. We had taken the Sulphur Mountain cable car to the viewing platform. On a clear day the view was nearly a hundred miles. The observation deck was crowded to capacity with tourists from all over the world. My parents and sister were talking to a couple from England when I left for the unusual building along the mountain's North ridge.

Physicists have a primal need to explain things as deeply as time and their audience's patience and curiosity permit. Almost immediately I was learning a bit about cosmic rays, muon showers, scintillators, photomultiplier tubes and so on until my father showed up. He had been looking for me for a few hours and happy wouldn't be the right word to describe his mood.

The ride down the mountain and then back to our camp was quiet - I knew better than to say anything. That didn't seem to matter at the time. I was completely engaged in what I had seem. Most of it was over my head, but seeing the existence of the remnants of a cosmic ray shower on a simple detector someone put together solely to explain what they were doing hit me deeply. I saw the beginnings of how people ask questions of nature and it had nothing to do with looking up things in a book. By the time Lyra was overhead I feel asleep knowing I would be either a physicist or an astronomer. It was a calling.

A month later I tagged along with my father on a trip to Los Angeles. He was taking a ten day workshop for a certification and I was seeing California for the first time. Friends and family recommended trips to Disneyland, Knott's Berry Farm, Hollywood, the beach and other things kids are supposed to see in Southern California. I wasn't interested and probably to my father's dismay managed to get my way. I visited JPL, and earthquake observatory, the planetarium at Griffith Park , and the La Brea Tar Pits.

Years later in grad school I came across a survey by the American Physical Society of recent graduates . A large majority of US born recent Ph.D.s, over 80%, had been raised in rural areas or near a natural history museum. This wasn't true of undergrad declared majors who mostly changed majors along the way but those who made it to the end were predisposed to have been in areas where some contact with Nature was likely.

Perhaps some areas are richer in sparks than others.

Some say kids are natural scientists. I disagree. Kids are wonderfully curious, but science isn't a grown-up version of child-like curiosity. Doing science requires learning and practicing abstract skills that are often not intuitive. Older students who have problems in something like a college chemistry class haven't unlearned an earlier ability, but rather

A few kids manage to get struck by a spark and dive in seeing the learning and work as play. This teenage dedication is far from unique to science. Music, sports, mechanics, art ... many kids spend their time picking up and honing basic skills that allow them to progress. These skills can be picked up at any time, but there are some kids who have a great head start - it isn't native intelligence as much as it is learning deeply.

There are two gaps that need to be jumped. First the initial spark, the calling for some, and then a longer gap that makes it possible to enjoy developing a somewhat different type of thinking than they're getting in school. This longer spark is a form of play.

The best day of the year at the old Bell Laboratories was the 24th of December. Employees brought their families and kids would wander around and see some real research often with some enthusiastic guides. Some departments went all out preparing demonstrations for the kids. After a few years kids became bored. They had home computer games were more interesting than anything at the labs. By the mid 90s kids weren't coming unless their parents dragged them along. Bell Labs had become a mostly spark-free environment. Where do you find events with spark potential these days?

Thinking about this earlier today I remembered the Lexus Hover Board ad...

The ad is real without digital special effects. It took me back to my first course in statistical mechanics. The professor was a low temperature theorist. We had been studying some of the oddities of liquid helium and he showed up with a dewar, a large beaker, a strip of metal and a magnet. The metal went into the beaker and was covered by the expensive liquid helium near absolute zero. He dropped in the magnet and we watched it levitate skittering around over the superconductor almost without friction. In the helium the metal had become a superconductor. The superconductor allows current to flow without resistance. When a material becomes a superconductor it excludes magnetic fields.

The field of the magnet induces current loops in the superconductor that exactly cancel the magnet's field. The magnet 'sees' a mirror image of itself and levitates. Its called the Meissner Effect.

Demonstrations like this fill your mind with questions and are entirely worth the cost of a bit of helium (there were only a eight students in the class). After Back to the Future II showed the Mattel Hover Board it was common to ask students to calculate what it would take to build such a device.

It gets even better...

Improvements in superconductors made it possible to levitate with (almost) dirt-cheap liquid nitrogen. In addition to the Meissner Effect there is something closely related called quantum flux trapping or flux pinning. I won't get into the details, but where the Meissner Effect shields the superconductor from the magnetic field, flux from the magnet enters tiny sites and is effectively pinned in place. With a bit of care you can fix the height and orientation of levitation and move objects along almost without friction.

Once you get a handle on flux pinning the Hover Board is just a matter of money.

These days there are any number of interesting YouTube videos. PhysicsGirl is doing terrific work that should inspire teenagers - particularly girls - much more than expensive produced television like Cosmos. That said I believe there is a need to see things for yourself and then begin to explore them on your own using real Nature rather than just watching videos or playing with simulations. This is partly broken, but perhaps we're seeing the start of it return. It is this hands-on component that encourages the hard work and experimentation necessary to move from the curiosity of a child to that of a scientist. Of course sparks for many things can come at any age - most of us are too busy to follow up, but every now and again something dramatic happens.

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Recipe Corner

An end of Summer salad. There are so many ways to go, but here's tonight's with sweet potatoes, apple and corn

09/11/2015

A large portion of the human brain is devoted to processing vision. We turn light collected on two small surfaces into electrical signals that are converted into a rich three dimensional model of the world around us. Simple tasks like catching a ball turn out to be beautiful examples of Newtonian physics. Observing the world gave us a huge supply of problems at many levels of difficulty. Over the centuries we worked through Nature's hints and problem sets developing amazingly predictive theories about how the Universe works along the way.

I sometimes wonder what discovery of physical law and art would be like for other animals if they had brains as powerful as ours. Dogs with their sense of smell probably wouldn't notice as much of the beautiful geometry in the sky. They'd probably concentrate on odors and would develop a science centered on chemistry. Their art would be very foreign to us - stories with rich plots on top of plots where observation is of the past rather than the present and time is calculated by the decay of an odor.... Whales are acoustic specialists, but the sounds they're sensitive to doesn't allow precise imaging. Their intuitive geometry might not be very crisp and what we think of as simple constructions might be abstract. Their vision isn't very good so they wouldn't be finding the patterns in the sky.

Our physics and math progressed to a point but finally intuition beyond visual observation became important. We struggle with what the equations suggest and rely on private visualizations to make sense of abstract fields like quantum mechanics and fields. One has to wonder if intelligent spiders might might have several legs up on us grasping field theory.

Nature allows many lines of questioning - but I'll admit to being biased towards vision.

Visualization is a necessary skill in much of science. More than a few physics departments offer courses through art departments to improve drawing and visualization skills. I suspect most people who end up in science have been sketching and visualizing for years.

I've been drawing as long as I can remember. I remember the kinetic joy of finger painting, but the real freedom came with pencil and paper. My Dad would bring home rolls of inexpensive butcher paper and let my sister and I go at it. We'd draw for hours. Time slowed down or just disappeared as drawings just emerged. Then we'd be pulled out of our trances for dinner or bed. It is the first time I can remember falling into a state of flow.

I still draw and sketch quite a bit for recreation and thinking. Paper is an amazing technology when you think about it, but I would love to be able to easily capture my drawings digitally. I've spent a fair amount of money and effort trying to do this, but nothing has been satisfying. When something is important I hunt for paper and pencil and then scan or photograph it if it needs to be digital.

With this as background, Apple's iPad Pro announcement caught my attention this week. I haven't tried one, but it may get me past the flow boundary. If you don't know about it, take a look at Apple's promotion video from the announcement a few days ago:

This isn't a normal iPad. iPads use a pointing device that, although convenient, isn't terribly accurate. I use my iPad 3 for reading, browsing, email and other forms of communication, reading and even editing music and photos. I leave my laptop at home when I travel. It is very good at what it does., but...

the regular iPad fundamentally fails as a drawing device

Sure you can do some simple drawing and any number of styli are on the market that are a bit more accurate than a finger. When I was a toddler I progressed from my finger to a pencil. I want a digital device that feels like a pencil on paper.

Currently most digital artists use Wacom tablets - digitizing tablets that use a pen. The tablet is usually held at a right angle to the screen. Precision work is possible, but my hand feels disconnected to the drawing surface. Additionally there is a bit of latency - sometimes you pen is moving faster than the image on the screen. Flow is elusive.

Some artists use Cintiq screens. They're an LCD screen that is sensitive to a pen. Think of them as iPads with much better pointing accuracy. In theory they're what you need, but there are some issues.1 They have low resolution color screens separated by a thick piece of glass. The image surface is far removed from the drawing surface causing parallax problems. The screens tend to be heavy. They're heavy, very expensive and need to be connected to a PC. There are often driver problems when new OS and drawing software appears. But there're the best thing going.

I need something that is accurate to the pixel level, and has a very low latency - the lag between moving the pen and having the image respond. The Cintiq I used had a best case 25 millisecond latency. Flow is very difficult to achieve if your image can't keep up with your pen. The other issues, particularly the parallax, were annoying, but latency killed it.

The iPad Pro, if it is as good as the video suggests, is an enhanced iPad.2 It is just an iPad until you need the precision drawing demands. Microsoft completely blew their demos when they showed crude drawing that is cleaned up in software and crude lettering - you can do that with your finger. Some, not all, need to go beyond that.

For it to be useful I think I need a latency below 10 milliseconds. I know I can detect and feel 15. I keep asking if artists have tried it and there is some indication this may be in the right ballpark. Apple is using faster sampling and screen drawing when the pencil is in use, so maybe ... If it isn't quite there, they'll probably improve in the next year or two. There are other issues like screen and pencil feel, but I think I can forgive them if everything else works.

So is this the iPad for everyone? Certainly not.3 A normal iPad is more than enough and is something of a PC replacement for many. But if you're a kid or draw, you would want a responsive and accurate pencil when you need to use it. If you draw a lot the pencil is just an extension of your hand - you don't think about it as a drawing instrument.4

Rarely to I see technology that makes me sit up. This is one of those times. It is spendy, so I may wait a year for a more responsive model and would probably go for the standard sized iPad if the feature is extended throughout the line. But we're getting close to computationally enhanced paper...

I'll leave with a video featuring an artist I met several years ago at Disney. Glen Keane draws for the joy of it. The video captures a bit of why you draw early on. He moves on to a VR drawing tool that asks some interesting questions, but I'm more interested in drawing itself - when you can just draw and flow away.

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1 I used one quite a bit four years ago and tried a much better one last year. The newer model was better, but is far from what I need. Would I take one if someone gave it to me? - no...

2 I've tried a Surface and would have bought one if it worked to my needs. I fails the latency test. Would I take one if someone gave it to me? - no...

3 Apple appears to be positioning this as a business tool in addition to the creative niche. Would I take one if someone gave it to me? - certainly (donations welcome:) Would I pay $1k for one? - maybe, but it would have to past my accuracy and latency hurdles.

Perhaps a more interesting question is would this be more appealing if it ran OS X rather than iOS? File management is important for art. Great art programs already exist.

4 You may have seen the pen called a pencil. A pencil is frequently a better device than a pen for sketching. I think used a better term.

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Recipe Corner

Sesame noodles adapted from an old newspaper recipe from ages ago

Cold Sesame Noodles

Ingredients

° 1 pound Chinese egg noodles from an Asian grocery.

° 2 tbl sesame oil

° 3 tbl soy sauce

° 2 tbl Chinese sesame paste

° 2 tbl Chinese rice vinegar

° 1 tbl peanut butter

° 1 tbl white sugar

° 1 tbl grated ginger (fresh is important)

° 2 tsp minced garlic

° 1 to 3 tsp chili-garlic paste (I like 2, but depending on how hot you like it)

° half a medium cucumber peeled and seeded but into 1/8" matchsticks

° 1/3 cup chopped roasted peanuts (no skins)

Technique

° Add noodles to a big pot of oiling water and cook 'til tender, but slightly chewy. Drain and rinse with cold water. Toss with a bit of sesame oil

09/01/2015

Dianna Cowern's work is great. Such delight and enthusiasm - it speaks highly of MIT:-) Her work, imho, is more important than that of people like Neil deGrasse Tyson as it is so much more accessible and manages to communicate the wonder on a personal level. I've met her and you're seeing an authentic science lover. She's also a terrific role model for girls. Her YouTube channel has grown to the point where she now has the support to do this for a living.

Formal K12 science education generally focuses on memorizing 'facts' and is too often distant and dry. There is no better way to kill an interest in physics and astronomy than a first semester course in physics that focuses on statics and math technique. The other sciences don't seem to fare any better. It isn't any wonder that many people who go on to science talk about learning outside of school when they were kids.

Over the years there have been attempts to support teenage amateur science. Unfortunately some of it misses the mark. The big ticket items when I was young were telescopes, microscopes and chemistry sets. Inexpensive optical instruments are usually bad and manage to find their way into the basement or the back of a closet. The chemistry sets weren't much better with manuals that replicated the non-excitement of a high school chemistry lab with boring cookbook experiments. The only attraction for some kids was the the fact that it could be a bit dangerous, but over time safety concerns rendered the kits about as interesting as a cake mix.

Such a shame as chemistry can be beautiful to the point of revelation. People have talked about a clueful chemistry set for teenagers and adults for decades, but that would take a serious commitment of time and money.

You'd be hard pressed to source the bits and pieces for less - I'd recommend going all the way if you're remotely interested. A responsible teen will probably manage to keep all of their fingers and eyebrows, so there isn't much worry. An adult with any imagination might discover a part of the world they didn't know about. For some this may be more exciting than a trip to an exotic location. But I'm talking about potential - the information so far is promising, but the important part will be the suggested experiments and explanations. Perhaps an online community will form around the project to add some depth.

It makes me wonder about what it would take to build a kit to explore physics at home.1 Much of physics involves seeing the unseen and smartphones have the computation power and a display that can dramatically lower the barrier. It just isn't physics. Instruments that extend or add to your senses are fundamental to the study of nature. The ability to do time lapse photographic studies, good enough digital microscopes, ultrasonic microphones, spectrographs, ir image sensors, and more. I was even able to find the normal modes of vibration of my living room during a hurricane using the three axis accelerometer in my iPhone. Much of this is pure gee whiz play early one, but some will want to understand at a slightly deeper level. The same instruments still work. Even serious mathematical investigation is being made more accessible with student versions of tools like Mathematica.

Perhaps there are even social uses. I didn't date until well into grad school. Dianna has a nice video showing something I used on my first date. (ok - I was pretty clueless).2

This is great stuff.

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1 I could get serious about this. As a kid I was fascinated with vacuum tubes, light and sound and spent a lot of time playing. Prisms, mirrors, a camera, filters, a borrowed tape recorder and so on were important tools. All of this along with amateur radio and learning how components work singly and together. You end up building a physical intuition that comes in handy at later stages when you get into more mathematical theory. You manage to gain a sense that you are asking the questions rather than just following someone else's cookbook.

2 An interview of Physics Girl Listen and imagine what science education could be like if at least ten percent of the instruction time focused on wonder. We need a group of treasures like her. Sort of RadioLab for lean forward science teens.

06/01/2015

Since I have an interest in ubiquitous sensors and computation many people assumed I'd get an Apple Watch the moment it came out. Something more interesting happened and I found myself with questions about what computation on the wrist is good for and the limits of what a wrist worn timepiece can do.

First I tipped my hat to Horace and starting thinking about the jobs to be done. Beyond cheap watches are camps of those who have an interest in different devices:

° a smartwatch that mostly tells time

° a wrist networked/computing device that happens to tell time

° a fine mechanical watch

None of these camps are right or wrong. In addition some people will use watches to signal social class or just enjoy the design and construction of a watch. Time keeping is central to some of these cases - particularly the mechanical watch - so it is useful to think of the jobs they were originally hired for - when innovations occurred and if innovation continues.

Navigation and event synchronization are important functions for accurate portable time pieces. Navigation is a fundamentally important driver of technology.1 Event synchronization became very important as the Industrial Revolution developed. There was a need to coordinate groups of people. Town clocks and home clocks that were synchronized to the town clock were important. The town clock would be set by the Sun's position - local noon could be determined and the clock could be adjusted regularly to good enough accuracy.

Railroads presented new problems. Every town had its own version of noon. Tables were produced showing the time offsets for clocks in other cities. Some stations kept clocks for each destination and hundreds of confusing charts were developed. Scheduling was a nightmare. Some crews would carry a half dozen clocks set for each major stop on a route. The clocks often lacked enough accuracy making matters even worse.

The solution was to standardize time. In 1840 Great Western Railway adopted London time. Within seven years most English railroads followed and finally a rail standards body recommended using Greenwich Mean Time. Local clocks throughout England followed, although many had two minute hands - one for local time and the other for GMT, and by about 1880 GMT was defined as the time throughout England. Other countries followed and time zones very roughly following divisions of longitude were established.

Pocket watches were reasonably accurate portable time pieces and the advent of standard time made them more practical beyond their original use on railroads. Some were beautifully built and expensive signaling social status in addition to giving the time of day. Wrist watches became accurate and durable enough to become important tools of military synchronization during WWI and mass production built an industry lowering prices to eventually make them a mass market item.

A decade before WWI a Einstein published one of his revolutionary results. He combined the experimental result that the speed of light was always constant with deep thinking about what the synchronization of events means and came to the conclusion that the measurement of time and that of space were not rigid. Moving clocks would run slowly and moving objects would shorten. Unless you could travel at a good fraction of the speed of light these effects were small. You would need a special clock that was much more accurate - more than a million times more accurate - than any known clock.

While I'm impressed by beautiful craftsmanship and design, I'm more taken with tools that allow revolutionary ideas to be discovered and verified. I see an Apple Watch or the best conventional watches and think about their accuracy compared to what it would take to verify special relatively. Such a watch would be impressive and more pure as a time keeping object. A regular watch does other jobs for some, but is only a time keeper for me.

Consider what it would take to verify the effect of special relatively by doing a thought experiment Einstein suggested. Place a clock in a moving vehicle and compare the time it shows to that of a clock that stays put with you. A nice trial would be to fly a clock around the world. Imagine an airplane going about 500 miles an hour on a 48 hour trip. A bit of calculation shows the airborne clock would show 47.99999999999867 hours had passed. You need a wicked good clock to see the difference.

It turns out atomic clocks are good enough. In October, 1971 the experiment was done by J.C. Hafele and R.E Keating. Two Hewlett Packard atomic clocks were flew in opposite directions around the world for about $7,600 in airline tickets for the crew and "Mr Clock". Analysis was complex as both Special and General Relativistic effects were involved.2 This was probably the least expensive new experiment involving General Relativity.

Portable watches won't give the required accuracy and why would you need it anyway? Watches can be synchronized GPS signals. They drift little enough between synchs that it is difficult to imagine a human level task they would fail at for lack of accuracy. But people have pushed the accuracy of standalone watches - atomic clock based watches and pocket watches have been built, but the atomic clock module they're based on isn't good enough to duplicate the 1971 flight around the world.3

The Apple Watch goes beyond time keeping allowing more convenient alerts and some health monitoring and encouragement. That isn't my use case - at least not yet. There will be many other sensors that it will be able to receive data from - a few hours thought gave me a list of a dozen that aren't crazy. That's where I'm hooked. If I had the time and inclination I'd be developing one or two now, but I rest assured many others have the same thought and some will be excellent developers.4

For me the Apple Watch represents future potential. When you see me with one consider it a signal that I've found something deeper that is beginning to get into the ubiquitous computation world.

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1 I touched on it here. The subject is rich and one could write for hours. Fortunately many others have and the history of science and technology has rich stories.

2 Special Relativity for the relative motion of the clocks and General Relativity to adjust for gravitational redshift. For the eastward flight theory predicted 144ns gained from GR, 184ns lost from SR giving 40ns lost total (+/- 23) and 59ns lost +/-10 was measured.

The atomic clocks were stock HP-5061A Cesium beam atomic clocks made in the mid 60s. They weighed about 80 pounds each and required a separate power supply - semi-portable.

The paper is great fun.

J.C. Hafele and R. E. Keating, Science 177, 166 (1972)

3 DARPA funded development of a miniature atomic clock for GPS denied navigation. It was commercialized by Microsemi as the Quantum SA.45s. Very nifty and even inexpensive at about $1,500 for the module, it is useful in underwater navigation and some military applications where GPS signals are unreliable. As atomic clocks go it isn't very accurate - not enough for testing special relativity unless you are at orbital speeds.

There are many other questions. The world has standardized on an ITC time reference based on the Earth's rotation. Unfortunately this varies quite a bit, slowing down beyond tidal drag and leap seconds need to be added. The physics and geophysics involved is amazingly rich. We should probably move to just basing time on atomic clocks, but there is institutional pushback.

A quick note on time standards. Coordinated Universal Time (UTC) is a standard and not a time zone. All timing centers on Earth have agreed to synchronize their time scales with it. There are two components of UTC -

Universal Time (UT1) is solar time and is based on the Earth's rotation. It is adjusted several times a decade with leap seconds to adjust for unevenness in the Earth's rotation.

International Atomic Time (TAI) is a time scale that uses the output of about 200 precision atomic clocks around the world.

03/15/2015

In high school you probably learned about the properties of infinite series. Things like the sum of the reciprocals of the powers of 2: 1/1 + 1/2 + 1/4 + 1/8 + 1/16 + ... converges on 2, but the sum of the reciprocals of the positive integers diverges: 1/1 + 1/2 + 1/3 + 1/4 + 1/5 + ... , growing to infinity. There are any number of interesting convergent series related to really interesting numbers like e and Pi, not to mention it is useful to know when something blows up to infinity. Math just works, eh?

But wait...

A friend sent a link to a video that seemed wrong. It made a completely nonsense claim: that the sum of all positive integers was not infinity. 1 + 2 + 3 + 4 + 5 + ... + infinity. Stranger yet was the claim it was not an integer and also negative. The video came from real mathematicians who sounded confident. He looked for an April first posting date, but didn't find anything suspicious. This had to be some kind of joke. What was the trick?

It turns the video is correct. In fact you need to be able to do sums like this if you want to use the Standard Model in physics as well as string theory and a few other areas. The same folks put out a second video with a bit more math, but still at a high school level. If you're really curious take a look.

Something extremely interesting is going on.

Imagine math in the days when the only numbers people used were real and rational. Some clever person came along and started using square roots. The square root of 1, 4, 9 and 16 made sense, but 2 was a problem. You could approximate the square root of 2, but it wasn't a rational number. A new type of math had been discovered that was not only was in another context, but expanded the notion of what math was.

On the surface the square root of a negative number seems pure nonsense - so much that the operation was defined as invalid on that side of the number line. But its just math, so why not? The square root of a -1 was defined to be a new type of number - an imaginary number. A new number system had been invented. It was shown to be rigorous in the proper context with certain definitions and has enormous value in physics and all of engineering.

This is the story of math. It is not a pristine temple where people work with pure logic using only existing truth to find new truths. Rather it is a bubbling sea of conjecture and relation. Ultimately a rigorous path needs to be found, but the frontiers are messy. Change comes with rebellion.

Leonhard Euler was just such a rebel. He wondered if sums that diverged to infinity had deeper meanings. Some, like the sum of all positive integers, had a regular structure. How might they differ from other infinite sums? Was there a story different from the final tabulation at the end?

He came up with an ingenious technique and showed the sum of positive integers was -1/12 in a fashion not too far from that of the first video. The first time I saw it in college was electrifying. It was like sorting through an infinite pile of dirt and rock to find a tiny diamond. When a similar series appears in quantum electrodynamics - an area of physics that gives us the highest precision of all measurements to date - you substitute in the little diamond and, low and beware, the calculation produces a meaningful result. The most accurate measurements humans have made agree with a theory that makes use of this type of sum.

Euler worked out several other series. The sum of the squares of all positive integers turns out to be 0 and that of the cubes is -1/120. In fact the all of the sums of even powers of the the integers is 0 and the odd powers is not. (Impress your friends by noting the sum of xi10 over i = 1 to infinity is 0.) He was unable to prove this rigorously. That had to wait about a century for Bernhard Riemann who was able to show a deep connection with something that fascinates to this day - the Riemann zeta function.

So what seems both wrong and crazy turns out to make perfect sense in a certain context - a context that is fundamentally related to how we know the physical world at the deepest level. Why does Nature seem to speak math? Now there is a deep mystery...

I should stress that the equivalence here is something of an issue. This gets deep into the analytic continuation of the Reimann Zeta function at s = -1 ... which happens to correspond to the sum of the positive integers. The videos don't stress it enough, but analytic continuation is probably too abstract to include.

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Recipe Corner

I don't know where the okra is coming from these days, but some is very high quality. I threw together a sort of crispy bhindi. Not exactly traditional, but delicious. As usual the quantities are recollections of what I think I did

Crispy Okra

Ingredients

° a pound of okra with the tops trimmed and sliced lengthwise into thin strips

° 1-1/2 tsp red chili powder

° 1-1/2 tsp garam masala

° 1/2 tsp turmeric

° 2 tbl chickpea flour

° 1 tsp cornstarch

° juice of one lemon

° vegetable oil

Technique

° mix the chili powerder, garm masals, turmeric, chickpea flour and cornstarch and toss the okra in it moistening with the lemon juice

° heat some vegetable oil in a wok to something under its flash point and fry a handful of okra at a time until golden. Drain on paper towels and let cool.

° I tried a second frying on some which makes them even crispier -- experiment!

02/26/2015

There is a considerable amount of confusion involved in the reporting of today's FCC network neutrality decision. Rather than getting into it and my bias, I suspect it might be more useful to spend a bit of time talking about what the Internet is and isn’t.1

A few weeks ago I wrote a post noting there were myths about the Internet and hinting I needed to say more. That’s a good starting point. I don't have much time tonight, but it is the right time to talk about the basics. Don't think of this as a history. It just highlights a few bits of brilliance.

Packet networks were invented in the 60s. The basic notion is information could be encoded into a digital form and grouped into packets that could be guided around a network. In the late 60s the spiritual predecessor to the Internet, ARPANET, went live linking (sort of at first) UCLA, SRI, UC-Santa Barbara and the U of Utah. A few other networks were established and a few services came along (email in 72 from BBN). By the mid 70s there was a Cambrian explosion of network types. There was a lot of freedom in what you could do and funding from the military (in the US at least). Engineers *love* to optimize. They would understand the problem at hand and go out and invent a protocol and network type optimized for that particular problem. The big engineering universities were supplying professors and grad students with dozens of Ph.D.s being generated on very lovely specialized solutions.

An exciting time, but two events changed the world. Bob Kahn and Vint Cerf proposed a very simple protocol and ARPA did something unexpected and wonderful.

The folks at ARPA worried a tower of Babel was being constructed. They were charged with coming up with something ultimately useful to the military and sought commonality. The simple solution was to declare a winner, but ultimately technology would have obsoleted it. Instead they formed a working group of the best computer scientists looking for something that would scale across technology, size and time. A serious rethink of networks was launched.

The realization was the heart of the matter was simple - just messages and addresses. A network sends a message from one address to another and a reply is returned telling the sender the message has made it. The protocol for what a packet should look like is published and it really doesn’t matter what the physical network is - it could be coax cable, a radio signal, a flashing light or even sound waves underwater. You could connect groups of these networks into something larger as long as everyone agreed to the same protocol and someone would construct a gateway to let the messages flow across boundaries.

Technically it was an overlay protocol. For specific applications it generally isn’t efficient. Engineers hate this sort of thing. AT&T pulled out sensing it was ugly and, of course, it violated AT&T’s core DNA of centralized control.

It may not have been locally efficient, but it was pure beauty if you wanted something that worked for almost everything. They had realized a great truth:

Optimization that becomes standardized kills innovation.

ARPA had created a working hourglass model. It didn’t depend on the technology underneath (the physical part of the network and its operation) and it doesn’t control or anticipate the types of uses that appear on top. It is close to a minimal set of what can work fairly well while allowing technology to constantly change and new service types to be created.

A mechanism where proposals for protocol changes and new service types that were low level was made.

People began to play. It suddenly became very useful to stitch networks together. In the late 70s this was ugly (I was involved in bringing two together as a hobbyist). By the early 80s a protocol was agreed upon and peering arrangements were negotiated between groups - ‘I’ll carry your traffic if you’ll carry mine’. Lots of innovation and technical change, but that thin middle layer was largely untouched.

It started to be known as the Internet. Noncommercial and mostly researchy those who used it in the day were building our own little clients and services for their own needs. The late 80s saw rules from Congress (largely Al Gore who was trying to fill his father’s TVA shoes) that led to explosive growth on campuses. Later commercial traffic was allowed...

AT&T and probably other carriers were happy to sell T1 and T3 lines to Internet service providers and colleges to support this quirky little non-theatening network. They had their own plans for a centrally controlled network - as late as '93 or '94 they believed the big packet network would come from specs to be written by the ITU in Switzerland.2 The carriers were sideswiped and stunned when the commercial Internet finally became available to normal people using this nifty world wide web that came from physicists at CERN - folks who had a problem and figured a solution could easily ride on the Internet.

That’s it - the history isn’t terribly important. It is just addresses and messages. Optimization was the enemy. There are very few examples of technologies that scale across time and technology. The Internet is probably the most important example.

__________

1 There are many legal issues in the FCC's rule. Barbara van Schewick is a Stanford law professor who specializes in the topics. Check out her blog to stay up to date for a deep dive away from the ISP bias.

2 It should be noted that most of research at Bell Labs was convinced the Internet would ultimately rule. David Isenberg's dumb network paper was somehow allowed to be published on the outside, but it was an articulate and thoughtful summary of the feelings of those of us who were in play mode.

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Recipe corner

In the spirt of a quick post just a simple idea. Winter squashes are still good, but dealing with big hard ones can be frustrating. Here's a trick. Wash the squash and find a pot large enough to hold it fully immersed (more or less). Put the squash in the pot, add water and now remove the squash. Heat the water to a simmer and now add the squash. Let it simmer for two or three minutes. If it wasn't fully immersed, take it out and flip it letting it simmer another two or three minutes.

Now lift it from the pot and let it drain. You need to be careful as having it fall back in the water can splash and scald. - I use a couple of big spoons.

It should peel very easily with a normal vegetable peeler and the flesh slices easily.